Serum amyloid A protein in patients with acute myocardial infarction

The concentrations of four acute phase proteins were measured in sera of 40 patients with acute myocardial infarction (AMI) to evaluate their behaviour from day-to-day and to find out if they can serve for early prediction of postinfarction complications and mortality rate. Peak levels of serum amyloid A protein (SAA) were increased up to 5000-fold above the normal value and those of C-reactive protein (CRP) about 100-fold, 3 days after AMI. alpha 1-antichymotrypsin (ACT) and alpha 1-acid glycoprotein (AGP) peak levels were increased up to eightfold above their normal values. Patients who developed postinfarction complications had significantly higher SAA values on admission than those without complications (mean values of 379 and 45 mg/L, respectively; P < 0.0001). Using a level of 100 mg/L on admission as a reference value gave a reasonable sensitivity and predictive value for complications (73%) and a very good sensitivity (80%) for early prediction of fatal outcome. Patients with SAA values above this limit had double the risk of complications and four times the risk of a fatal outcome. The correlation with CRP values was lower than it was with SAA values (P = 0.028) using a level of 15 mg/L on admission as reference value gave low sensitivity (55%) and predictive value (60%) for complications as well as low sensitivity for early prediction of fatal outcome (60%). The present study did not allow prediction of complications or mortality based on ACT or AGP values.